Regulator for dynamo-electric machines



(No Model.) 2 SheetsSheet 1. R. H. MATHER.

REGULATOR FOR DYNAMO ELECTRIC MACHINES.

No. 384,712. Patented Jan. 19, 1886.

Evy/6711107 Q4 Wit/Z6886 M MM (No Model.) 2 Sheets-Sheet 2.

R. H. MATHER.

REGULATOR FOR DYNAMO ELECTRIC MACHINES. No. 334,712. Patented Jan. 19,1886.

W Gm States Parent RICHARD H. ll'lATHER, OF WINDSOR, ASSIGNOR TO THE MATHER ELECTRIC OOIiIPANY, OF MANCHESTER, CONNECTICUT.

LATOR FOR DYNAlViO-ELECTRiC MACi-HNES.

Application filed September 19, 1884. Serial No. 143,452.

(No model.)

To (ZZZ whom it may concern:

Be it. known that I, Rioniinn H. hLiTHER, a citizen of the United States, residing at \iViudsor, in the county of Hartford and State of Connecticut, have invented certain new and useful improvements in Regulators for Dynamo Electric Iiiachines; and I do declare the following to be a full, clear, and exact descrip tion of the invention, such as will enable others skilled in the art to which it appertaius to make and use the same, reference being had to the accompanying drawings, and to the let ters and figures of reference marked thereon, which form a part of this specification.

My invention is an automatic regulator for that class of dynamo-electric machines commonly called shunt-dynamos.

The object of my invention, as applied to a dynamo-clcrtric generator of the class men tioned, is to regulate the same in such a manner that it shall produce a uniform and constant current in the \vorlcingcircuit regardless of variations in resistance in that circuit a result which is particularly desirable in the use of such machines in electric-arc lighting. My invention when so applied is designed to render such generator capable of operating with a constant current any number of electric-arc lamps or other resistances arranged in series, up to the full capacity of the ma chine.

My invention also relates to automatic regulators for electric motors, the latter term be ing here used in a broad sense, including magneto elect ric as well as dynamo-electric motors.

The object of my invention as applied to an electric motor to regulate the same in such a manner that such motor, when supplied with a constant elcctro-inotive force, shall run at a constant speed, whatever the work,or no work, which it may be. doing. My device foraccoinplishing this object is a variable magnetic switch or shunt consisting of an armature or keeper of the Lind-magnet, which armature is a differential electromagnet, and may for convenience be termed a compound dctractor.

In the accompanying drawings I have represente dynamo embodying my invention in two of its forms.

Figure 1 is a diagrammatic representation of my invention as applied to a typical sauntdynamo with arc-lamps in the main circuit, and Fig. 2 is a diagrammatic representation of my invention as applied to a typical dynamo-electric motor whose field-magnet is shuntwound.

In the drawings, F is the field magnet, whose particular form is unimportant in this connection. The north and south poles of the field-1nagnet, which are lettered, respectively, N and S, should, however, be of convenient form for contact with the detractor, as hereinafter mentioned.

A is the revolving armature, provided with commutator and brushes in the usual manner, as shown.

D is the detractor, which is a core of soft iron, wound differentially as an electro-inagnet, and having north and south poles, or polepieces, which are lettered, respectively, N and S, and are of any convenient form for ample contact with N and S, before mentioned, as shown. The principal winding of the detractor, and that which determines the polarity just stated, is by means of a fine wire in a shunt-circuit forming the helix [1. This wire should preferably be of the same size as that which is wound upon the field-magnet. The detractor-helix hand the field-magnet helix are preferably placed in one and the same sliuntcircuit, as shown. The direction in which the electric current is to circulate in said helices, as dependent upon the direction of winding, or the manner of connecting the same, must be such that like poles produced thereby in the fieldmagnet and detractor shall be adjacent to each other, as shown in the drawings, in which position the field-magnet and dctractor should be fixed, and may be conveniently bolted together. The coarse 0 wire in the main circuit is wound upon the detractor in a manner to constitute the di eutial helix H, tending to neutralize or counteract the electromagnetic effect of the hellX h.

G is a generator which yiells a constant electro-motive force. Its positive and negative poles are indicated by the signs and respectively.

Confining my explanation to the case of the 1100 Having completed the machine in the usual manner as to all parts thereof, except the detractor I assume a detractorcore which is supposed to possess the required conductivity, and then, by the use of the magnetometer or by actual experiment, I ascertain what quantity of wire of a size selected for the purpose is necessary to produce in the assumed detractor, when wound thereon and placed in circuit, the same intensity of magnetization as can be produced in the field-magnet by the field-magnet coil in the normal operation of the machine when all the lights are on. Then I introduce a piece of wire of the size and quantity so determined into the shunt-circuit of the machine without placing the same upon the detractor. At this point I introduce into the shunt-circuit containing the field-magnet coil and the fine-wire detractor-coil a small artificial resistance, for the purpose which will hereinafter appear. Then placing in the work ing-circuitof the machine the maximum number of lamps which the same is designed to operate, I run the machine at such speed as will bring all the lamps to the desired standard of brilliancy. This is the normal speed of themachine. Before winding the detractor I next place the same,'unwound, in its position ofcontact with the field-magnet, as shown. At the same time, and while the piece of wire before mentioned remains in circuit, I turn out all the lights in the circuit except one and observe the result. If the single remaining light is too bright, I increase the conductivity of the detractor by increasing its mass, and if too dim I diminish the same by removing some of the iron from the detractor-core until the standard brilliancy is regained. This operation determines, with practical correctness, though not with theoretical accuracy, the required size and conductivity of the detractor-core. Then I wind the detractor-core with the piece of wire just mentioned, in the manner of an electro-magnet, as indicated in the drawings. The piece of wire just mentioned may now be subjected to any necessary correction ascertained by the use of the magnetometer or by experiment, in order that the same may be just sufficient to produce in the corrected detractorcore, when wound thereon and placed in circuit, the same intensity of magnetization as will be produced in the field-magnet by the field-magnet coil in the normal operation of the. machine. The corrected detractor-core being wound with the corrected piece of fine wire just mentioned, I proceed to ascertainby experiment how much coarse wire of the size used in the main circuit is necessary to neutralize in the detractor when wound thereon,in the manner of a differential coil, andwhen placed in the working-circuit with a single lamp,theelectro-magneticeffectofthefine-wire detractor-coiljust described. This quantity of coarse wire may be ascertained by the use of the magnetometer or by experiment. Next I place all the lamps in circuit and bring them to normal brilliancy by increasing to any necessary extent the fine-wire detractor-helix by the introduction of additional fine wire. At this point I remove from the shunt-circuit so much of the artificial resistance, before mentioned and introduced, as is equal to the resistance introduced into the circuit by such addition to the fine-wire coil of the detractor. Then I turn out all the lights but one and observe the result. If the single remaining light is too intense, I increase the coarse-wire detractor-helix by the use of additional coarse wire wound upon the detractor until the normal brilliancy is regained. This process determines with a fair degree of accuracy the size or winding of the respective coils of the detractor necessary in order that the lights in circuit, whether one or more, up to the capacity of the machine, may be of standard brightness. If a greater degree of accuracy is desired, the same process may be repeated by assuming at the outset the detractor core ascertained as above.

The remaining features of construction, as well as the appropriate connections, involved in this invention as applied to a dynamo-electric generator will sufficiently appear from the drawings, Fig. 1, and from the mode of operation, as hereinafter explained. This construction results in the following mode of operation: The detractor D is a magnetic shunt about the armature A. The magnetic conductivity of this shunt is variable in amanner which is the differential effect of thejoint operation of the detractor-coils. The detractor, when its conductivity is least diminished by action of the detractoncoils, shunts so much of the magnetism of the field-magnet around the armature A, and thereby so much weakens the field of force in which that armature revolves that a single lamp placed in the circuit will not receive an excessive current. When most diminished by the same cause, its conductivity is so little that the maximum number of lamps, when placed in circuit, will receive so much current as they require for standard brilliancy, and when affected by said coils to any intermediate degree the conductivity of the detractor is such that the intermediate number of lamps producing that varied effect will receive so much current as is necessary to bring those lamps to standard brightness, and no more.

It is wellunderstood that in the case of a shunt-dynamo having no regulator the current in the working-circuit diminishes as the number of lamps increases, for the reason that successive equal increments of resistance in the working-circuit and the corresponding equal increments of current in the shunt-circuit fail to produce equal increments of magnetization in the field-nmgnet. Accordingly the magnetization of the field-magnet, and hence the intensity of its field, increases less and less for each additional lamp turned on, and diminishes more and more for each lamp successivel y tu rned off. The detractor remedies this defect by producing for every lamp turned on or off an equal and uniform variation in the intensity of the field in which the armature revolves.

In the operation of the detractor it is the function of the fine-wire detractor-helix to diminish the magnetic conductivity of the detractor at all timesin the same degreein which the magnetism of the field-magnet is increased by increasing the number of lamps in circuit, and in like, manner to permit the magnetic conductivity of the detractor at all times to increase in the same degree in which the magnetism of the field-magnet is diminished by diminishing the number of lamps in circuit, andso to preserve a uniform conductivity in the detractor, so far as the same is affected by the fine-wire detractouhelix, as against all variations of electric current in the shunt-circuit. It is the function of the coarse-wire detractorhelix to increase the magnetic conductivity of the detractor at all times in the same degree in which the magnetism of the field magnet is diminished by diminishing the number of lamps in operatiomand to allow the magnetic conductivity of the detraetor, so far as the same is affected by this wire, to be diminished at all times in the same degree in which the magnetism of the fieldmagnet is increased by turning on lamps, and so as to cause the mag netic conductivity of the detractor, so far as the same is affected by means of the coarse Wire detractor-helix, to vary at all times in a ratio the reverse of that in which the magnetism of the field-magnet is varied by reason of the variations of the electric current in the shunt-circuit due to turning lamps on or off; hence the combined effect of the detractorcoils is to render the conductivity of the detractor inversely proportionate to the degree of magnetization produced in the field-magnet by the field-magnet coil with any number of lamps in circuit within the capacity of the machine. Thus the intensity of the magnetic field in which the armature revolves is by the detraetor caused to vary di rectly and uniformly as the number of lamps in circuit, and thus a uniform current is preserved, regardless of the number of lights or other resistance in the working-circuit.

Coming now to the electric motor illustrated in Fig. 2, I proceed to point out the construction of the detractor D more particularly, both in respect of the magnetic conductivity of the detractor as dependent upon its size or mass and in respect of the electromagnetic power of the detraetor-helices as dependent upon the quantity of wire contained in those helices respectively. In the construction of my invention as applied to any particular electric motor, I determine these particulars in the following manner: Having completed the motor as to all parts thereof, except the detractor, I assume a detractorcore which is supposed to possessthe required conductivity, but which is not sufficient, when applied to the fieldmagnet, to reduce the power of thelattermore than one-half, and then by the use of themagnetometer, or by experiment,I ascertain what quantity of wire of the size selected for the purpose is necessary in order to produce in the assumed detractor, when wound thereon and placed in circuit, the same intensity of magnetization as is found in the field-magnet in the normal operation of the motor. Then I introduce a piece of wire of the size and quantity so determined into the shunt-circuit of the machine, but without placing the same upon the detractor. Then I place the motor without any load in circuit with the generator and note the speed. This is the normal speed of the motor. Before winding the detractor I then place the same in its position of contact with the field-magnet, (shown in the drawings,) and with the piece of fine wire before mentioned still remaining in the shunt-circuit I load the motor toits fullintended capacity and observe the speed. If the latter is too low, I increase the conductivity of the detractor by increasing its mass, and if too high I diminish the same by removing some of the iron of the detractoncore until the normal speed is re gained. This operation determines approximately the required size and conductivity of the detractor-core. Next I wind the latter with the piece of fine wire just mentioned, in the manner of an electro-magnet, as indicated in the drawings. This piece of wire may at this point be subjected to any neces sary correction, ascertained by the use of the magnetometer or by experiment, in order that the same may bej ust sufficient to produce in the corrected detractor-core, when wound thereon and placed in circuit, the same intensity of magnetization as exists in the field-magnet in the normal operation of the motor. This determines the quantity of wire contained in the helix It. The corrected detraetor-core having been wound with the helix h, I proceed to ascertain by experiment how much coarse wire of the size used in the main circuit is necessary in order to neutralize in the detractor, when wound thereon as a differential coil, and when placed in circuit, the electromagnetic effect of the helix h when the motor carries a maximum load. This I accomplish by running the motor with a maximum load and winding on coarse wire until the normal speed is attained. This determines the helix H. These steps determine with a fair degree of accuracy both the quantity of wire which is necessary to be contained in the coils H and h, respectively, and the size which is necessary to be given to the detractor-core in order that the speed ICO I of the motor may be constant, irrespective of the load which is carried. If a greater de gree of accuracy is desired, the same process may be repeated, assuming at the outset the detractor-core already ascertained, as above. The remaining features of construction involved in this invention, as well as the appropriate connections, will sufficiently appear from the drawings and from the mode of operation, as hereinafter explained. This construction results in the following mode of operation: The direction of the current is indicated by arrows. The detractor D operates as a magnetic shunt about the armature A. The magnetic conductivity of this shunt is variable in a manner which is the result of the combined operation of the coils H h. The detractor, when its conductivity is least diminished by the action of the detractor-coils, shunts so much of the magnetism of the fieldmagnet around the armature A, and thereby so much weakens the field of force in which that armature revolves, that a maximum load placed upon the motor is carried at normal speed, and not less. When most diminished by the same cause, its conductivity is so little, and the magnetic field is consequently so strong, that a minimum load, when placed upon the motor, is carried at normal speed, and not faster; and when affected by said coils to any intermediate degree the conductivity of the detractor and the intensity of the magnetic field as affected by the detractor are such that the intermediate quantity of load which produces that varied effect is carried at the normal speed of the motor. It is well understood that in the case of a shunt-motor which has no regulator thespeed diminishes as the load increases, and conversely, for the reason that equal units of increase or decrease of load do not cause equal units of increase or decrease in the current which passes through the armature of the m0- tor.

The unequal and disproportionate variation of current attending variations in the load is caused by variations in the counter electromotive force of the motor,due to corresponding variations in speed. The present invention remedies this defect by producing for every unit of work placed upon the motor or taken off an inverse variation in the intensity of the magnetic field in which the .armature revolves. In accomplishing this result it is the function of the helix h'to cause the magnetic conductivity of the detractor to vary with the electro-niotive force supplied, and to cause the same to remain constant, so far as the effect of this helix is concerned, for any constant electro-motive force. It is the function of the helix H to cause the conductivity I of the detractor, so far as the same is affected by this h6llX,t0 vary directly with the current. Hence it is the combined effect of the helices H h to cause the conductivity of the detractor to vary directly with the current, whatever be the constant electro-motive force supplied, and

whatever be the consequent constant degree of magnetization produced in the field-magnet. Thus the intensity of the field, and consequently the back electro-motive force, are caused to vary inversely with the current; and these inverse ratios of variation in the counter electro-motive force and in the current are so nearly equal that a practical uniformity of 7 5 speed is by this means preserved, regardless of changes in the amount of work imposed upon the motor.

The application of my invention in the case of a magneto-electric motor and in the case of a motor having aseparately-excited field-magnet needs no separate illustration or explanation, either in respect of construction ormode of operation, forin these motors the detractor operates under the same conditions as in the typical shunt-motor already explained.

It is to be observed that by means of this invention the speed of the motor -is made to depend upon the electro-motive force supplied by the generator, so that the former may be controlled by regulating the latter; also, by means of this invention an electric motor may be adapted to utilize any constant and predetermined electro-motive force for the production of any required speed of running, regardless of the work which may be performed.

I claim as my invention and desire to secure by Letters Patent 1. In combination with the armature and field-magnet of a dynamo-electric machine, whether generator or motor, the detractor D, consisting of a magnetic core wound with the helices H h ,and provided with the pole-pieces N and S, substantially as shown, and operating as described, for the purpose specified.

2. In combination with the armature and field-magnet of a dynamo-electric machine whether generator or motor, a differential electromagnetic armature or keeper of the field-magnet, substantially as shown, and operating as described,for the purpose specified.

3. In combination with the armature and field-magnet of a dynamoelectric machine, whether motor or generator, a variable magnetic switch or shunt consisting of the core of a compound electro-magnet, substantially as shown, and operating as described, for the purpose specific 4. In combination with the armature and field-magnet of a dynamo-electric machine,

whether motor or generator, an electro-magnet wound differentially with two coils or helices, one of which is in the main circuit of the machine and the other in a derived circuit,

substantially as shown, and operating as de-' scribed, for the purpose specified.

5. In combination with the armature and field-magnet of ashunt-wound dynamo-electric machine, whether motor or generator,an electro-ma-gnet wound differentially with two coils or helices, one of which is connected in series and the other in parallel with the field-magnet coil,substantially as shown, and operating as described, for the purpose specified.

6. In combination with the armature and field-magnet of a dynamoelectric machine, whether motor or generator, a differential electro-magnet whose poles are respectively adjacent to like poles of the field-magnet, and one of whose helices is in circuit with the said armature independently of the helix of such field-magnet, substantially as shown,and operating as described, for the purpose specified.

7. In combination with the armature and field-magnet of a dynamo-electric machine, whether motor or generator, a differential electro-magnet whose helices are connected, one in series with said field-magnet and with the source of current of said machine, and the other in series with said armature and with the external work or source of current, as the case may be,substantially as shown, and operating as described, for the purpose specified.

8. In combination with the armature and field-1nagnet of a dynamo-electric machine,

whether motor or generator, an electromagnet wound differentially with two coils or helices, one of said helices being connected in series with said armature, and with an external source of current or working resistance, as the case may be, and the other of said coils being connected in parallel with said armature, or with such external work, as the case may be, substantially as shown, and operating as described, for the purpose specified.

9. In combination with the armature and field-magnet of a dynamo-electric machine, whether motor or generator, an electro-magnet wound diiferentially with two coils or helices, one of said coils being connected in parallel with said field-magnet and the other of said coils being connected in parallel with said armature, or with external work, as the case may be, substantially in the manner and for the purpose specified.

10. In combination with the armature and field-magnet of a dynamo-electric machine, whether motor or generator, a differential electro-magnet whose coils are connected, one in parallel with said field-magnet and in series with said armature, and with the external work or source of current of such machine, and the other in parallel with such Work or armature, as the case may be, and in series with said armature or external source of current, as the case may be, substantially in the manner and for the purpose specified.

In testimony whereof I affix my signature in presence of two witnesses.

RICHARD H. MATHEB.

XVitnesses:

GiLlRLns l-I. CLARKE, \VILLARD EDDY. 

